Portal:Solar System/Did you know/6

...that the Caloris Basin on Mercury, one of the largest impact basins in the Solar System, is surrounded by a series of geological formations believed to have been produced by the basin's ejecta?
...that Kordylewski clouds are large concentrations of dust that orbit Earth at the distance of the Moon?
...that no viable solution has yet been found to counteract radiation from space, which is a serious threat to astronauts on any future mission to Mars?
...that Claudia Alexander was the last project manager of NASA's Galileo mission to Jupiter?